Blockade of morphine analgesia by both pertussis and cholera toxins in the periaqueductal gray and locus coeruleus.
Rats demonstrating analgesia following microinjection of morphine into the periaqueductal gray (PAG) or locus coeruleus (LC) were injected with either pertussis toxin, cholera toxin or saline into the same brain region. Both pertussis and cholera toxin blocked the analgesic effect of morphine at both injection sites for up to 7 days after toxin treatment. These results indicate that morphine analgesia is a complex response involving systems dependent upon Gs as well as Gi or Go proteins.
Bodnar
R J
RJ
Cotzias Laboratory of Neuro-Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
Paul
D
D
Rosenblum
M
M
Liu
L
L
Pasternak
G W
GW
D000698:Analgesia; D000818:Animals; D002772:Cholera Toxin / Q000008:administration & dosage / Q000494:pharmacology*; D007700:Kinetics; D008125:Locus Coeruleus / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D008845:Microinjections; D009020:Morphine / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010487:Periaqueductal Gray / Q000187:drug effects / Q000502:physiology*; D037342:Pertussis Toxin; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D010566:Virulence Factors, Bordetella / Q000008:administration & dosage / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D009020:Morphine; D002772:Cholera Toxin; D037342:Pertussis Toxin